320th Missile Squadron, Missile operations squadron at Francis E. Warren Air Force Base in Cheyenne, United States.

The 320th Missile Squadron is a United States Air Force unit assigned to the 90th Operations Group at F.E. Warren Air Force Base, Wyoming. It is equipped with the LGM-30G Minuteman III intercontinental ballistic missile and carries out a nuclear deterrence mission. The squadron was reactivated as an ICBM unit on 8 January 1964 with fifty LGM-30B Minuteman I missiles.

The squadron was originally established in 1942 as a bombardment unit and transitioned to missile operations in 1964. This shift reflected the strategic changes in air defense during the Cold War era.

The squadron's name and number trace to the 320th Bombardment Squadron, formed at Key Field, Mississippi, in April 1942 as one of the original squadrons of the 90th Bombardment Group. Its World War II crews flew B-24 Liberators against airfields, shipping and troop concentrations in New Guinea, the Bismarck Archipelago, Palau and the southern Philippines, earning a Distinguished Unit Citation for operations in Papua through January 1943.

The squadron is based at F.E. Warren Air Force Base in Cheyenne, Wyoming, where its command facilities are located. Access is restricted to authorized personnel and requires adherence to the base's security protocols.

The 320th was the second of the 90th Wing's four Minuteman squadrons to activate, in January 1964, while construction on its launch facilities continued until mid-1964. Its Minuteman I missiles began giving way to Minuteman IIIs in June 1973. In 2001, treaty compliance cut each missile to a single reentry vehicle.